Most humidifiers presently on the market bubble the oxygen through water to pick up moisture. This is accomplished by passing the oxygen through a porous medium or screen which is located below the surface of the water. These so-called "bubblers" are limited in the amount of mass transfer they are able to achieve and will typically produce up to about 40% relative humidity (referred to body temperature) when operated at room temperature. An additional 10% may be achieved when a nebulizer is used as a humidifier. Both apparatuses depend upon the oxygen and water interfacing for a length of time and in such a manner that the contact is maximized. However during operation the operating temperature decreases and efficiencies therefore decrease.
An effective approach to increasing efficiency is to increase the molecular energy of the substances by heating. The addition of heat has been a standard scheme for increasing efficiency whereby the addition of small amounts of heat increase operating efficiencies to near saturation.
However, the nebulizer and humidifier units presently available in the art have many disadvantages and drawbacks. Many of them are quite expensive. Reusable units require special handling and sterilization.
Units with heaters have even more problems. Since these heaters have been either of the immersion type or the cuff type, they heat the entire water supply, thusly requiring a warm up time before operating efficiencies are reached and using large amounts of power. As a result they are quite inefficient. Moreover, these types of heating elements present a severe burn hazard. Most of them have high failure rates, require long down times for repairs and build up deposits which reduce operating efficiency quite markedly. Most units are quite bulky, taking up large inventory spaces.
What is desired therefore is an improved humidifier and an improved nebulizer, preferably a single unit with an interchangeable dual function. What is also desired are improved components for such a unit. An inexpensive and disposable nebulizer nozzle is needed. An inexpensive and efficient heating unit which is safe to handle and which heats only the water being used and when it is to be used instead of the entire water supply is also needed. A water container which is inexpensive and disposable and which is easily storable when not in use is needed. Safety features should be resident in the unit to protect the patient. Moreover the unit should be of a design which is easily and inexpensively manufactured and which is easily cleaned and repaired. Summary of the Invention
This subject invention involves a collapsible water reservoir for use with humidifier and nebulizer units used with oxygen breathing systems.
The reservoir may be a plastic bag which may be manufactured as disposable and reusable models depending upon the materials used. This bag may be prefilled and/or refilled as needed and may be stored unfilled or filled with sterile water.
A flat sheet of plastic may be heat sealed or otherwise attached to a second sheet of plastic to form the bag; the second sheet being preferably belled to naturally form a cavity therebetween.
A passageway may be formed to run from the top to the bottom and across the bottom of the bag. Alternately a dual passageway may be formed that runs across the top and down both sides as well as across the bottom. This passageway may be created by the sealing of a second portion of the two plastic sheets together. This seal may be discontinuous across the bottom section creating a diffuser thereby. The passageway may have an access opening at the top of the bag.
An access opening to the interior of the bag above the normal fluid level preferably exists in proximity to the passageway opening.
A mounting boss having a raised rib portion may be used to attach the bag to a humidifier and nebulizer operating housing. This boss preferably extends about the bag and passageway openings and has at least one cross rib which isolates these openings and therefore isolates their operating functions. This boss may be configured to engage in cooperative sealing functions as well as mounting functions with a housing. The boss is attached to and becomes an integral part of the bag.
An adhesive or heat sealed closure may seal the bag and passageway openings when the bag is not in use.